1. Field of the Invention
This invention relates to novel multibinding compounds (agents) that inhibit 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the rate limiting enzyme in cholesterol biosynthesis, and to pharmaceutical compositions comprising such compounds. Accordingly, the multibinding compounds and pharmaceutical compositions of this invention are useful in the treatment and prevention of hypercholesterolemia, hyperlipidemia, atherosclerosis and the like.
2. References
The following publications are cited in this application as superscript numbers:
1A. Endo et al., FEBS Letters 1976, 72, 323-326.
2P. Louis-Flamberg et al., Biochemistry 1990, 29, 4115-4120.
3H. Pang et al., Pharmacotherapy 1997, 17, 1157-1177.
4H. Bischoff et al., Atherosclerosis 1997, 135, 119-130.
5C. B. Blum, J. Cardiol 1994, 73, 3D-11D.
6J. D. Bergstrom et al., Biochim. Biophys. Acta 1998, 1389, 213-221.
7C. E. Nakamura et al., Biochemistry 1985, 24, 1364-1376.
8U.S. Pat. No. 4,963,538, issued Oct. 16, 1990 to Duggan et al.
9EP Publication No. 0 251 625 B1, published May 29, 1991.
10U.S. Pat. No. 4,739,073, issued Apr. 19, 1988 to Kathawala.
11B. D. Roth et al., J. Med. Chem. 1990, 34, 357-366.
12C. Chan et al., J. Med. Chem. 1993, 36, 3646-3657.
13G. Beck et al., J. Med. Chem. 1990, 33, 52-60.
14J. Robl et al., J. Med. Chem. 1991, 34, 2804-2815.
15C. M. Lawrence et al., Science 1995, 268, 1758-1762.
All of the above publications are herein incorporated by reference in their entirety to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference in its entirety.
3. State of the Art
Over the past 15 years, a number of new drugs collectively known as statins or vastatins have been introduced to reduce serum LDL cholesterol levels (representative examples of these drugs are shown in FIG. 1). High LDL cholesterol levels have been shown to be an important risk factor in the development of arteriosclerosis and ischaernic heart disease. The statins have been found to lower serum LDL cholesterol levels in a dose dependent manner. Additionally, these drugs lower serum triglyceride levels; another risk factor for heart disease.
The statins lower serum LDL cholesterol levels by competitive inhibition of 3-hydroxyl-3-methylglutaryl-Coenzyme A reductase (HMG-COA reductase), an enzyme involved in the biosynthesis of cholesterol.1-4 The two-step reduction of HMG-CoA is illustrated in FIG. 2. The statins, such as simvastatin, appear to be mimics or analogs of intermediate C shown in FIG. 2. By binding tightly to the active site of the enzyme, the statins block the reduction of HMG-CoA, a step necessary in the biosynthesis of cholesterol. This inhibition of cholesterol biosynthesis by the statins results in a decrease in the production and secretion of LDL cholesterol. In addition, the upregulation of LDL receptors, especially in the liver, leads to the removal of LDLs from the serum. Thus, by reducing the production of LDL cholesterol and by causing LDL cholesterol to be removed from the serum, the statins effectively reduce overall serum LDL cholesterol levels.
Two-thirds of the total cholesterol found in the body is of endogenous origin. The major site of cholesterol biosynthesis is in the liver. Such liver-derived cholesterol is the main cause of the development of hyper-cholesterolaemia. In contrast, cholesterol production in non-hepatic cells is needed for normal cell function. Therefore, selective inhibition of HMG-CoA reductase in the liver is an important requirement for HMG-COA reductase inhibitors. In this regard, the statins typically have high oral availability and high hepatic extraction during their first pass through the liver.5 
Even though the current HMG-CoA reductase inhibitors are quite potent, (i.e., having IC50""s in the range of about 1 nanomolar), a need exists for even more potent and longer lasting HMG-CoA reductase inhibitors. Tighter binding inhibitors would decrease the amount of drug that escapes from the liver and this, in turn, would decrease adverse side effects. Additionally, a longer plasma half-life appears to be associated with maximum cholesterol lowering.6 Thus, increasing the duration of effect of the inhibitor is expected to result in even lower serum cholesterol levels.
It has now been discovered that HMG-CoA reductase inhibitors having surprising and unexpected properties can be prepared by linking from 2 to 10 ligands capable of binding to HMG-CoA reductase to one or more linkers. Such multibinding compounds provide greater biological and/or therapeutic effects than the aggregate of the unlinked ligands due to their multibinding properties.
This invention is directed to novel multibinding compounds (agents) that inhibit 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase. The multibinding compounds of this invention are useful in the treatment and prevention of hypercholesterolemia, hyperlipidemia, atherosclerosis and the like.
Accordingly, in one of its composition aspects, this invention provides a multibinding compound comprising from 2 to 10 ligands covalently attached to one or more linkers, wherein each of said ligands independently comprises a moiety capable of binding to 3-hydroxy-3-methylglutaryl coenzyme A reductase and further wherein the distance between ligands is at least 10 xc3x85; and pharmaceutically acceptable salts thereof.
In another of its composition aspects, this invention provides a multibinding compound of formula I:
(L)p(X)qxe2x80x83xe2x80x83I
wherein each L is independently a ligand comprising a moiety capable of binding to 3-hydroxy-3-methylglutaryl coenzyme A reductase; each X is independently a linker; p is an integer of from 2 to 10; and q is an integer of from 1 to 20; and further wherein the distance between ligands is at least 10 xc3x85; and pharmaceutically acceptable salts thereof.
Preferably, q is less than p in the multibinding compounds of this invention.
Preferably, each ligand, L, in the multibinding compound of formula I is independently selected from the group consisting of:
(a) a compound of formula IA: 
xe2x80x83wherein
A1 is selected from the group consisting of: 
where IV is selected from the group consisting of hydrogen, lower alkyl and a pharmaceutically-acceptable cation;
R1 is selected from the group consisting of alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkynyl, substituted alkynyl, cycloalkyl, substituted cycloalkyl, alkoxy, substituted alkoxy, aryl, heterocyclic, amino, substituted amino, thioalkoxy, substituted thioalkoxy and thioaryloxy;
R2 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, acyl, acyloxy, alkoxy, alkoxycarbonyl, aminoacyl, aminoacyloxy, aryloxy, carboxyl, hydroxy, keto, thioalkoxy, thioaryloxy, xe2x95x90Nxe2x80x94ORd where Rd is hydrogen or alkyl, and a covalent bond attaching the ligand to a linker; or R2 together with the carbon atom to which it is attached represents a spiro-attached cycloalkyl group;
R3 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, acyl, acyloxy, alkoxy, alkoxycarbonyl, aminoacyl, aminoacyloxy, aryloxy, carboxyl, hydroxy, keto, thioalkoxy, thioaryloxy, xe2x95x90Nxe2x80x94ORd where Rd is hydrogen or alkyl, and a covalent bond attaching the ligand to a linker; or R3 together with the carbon atom to which it is attached represents a spiro-attached cycloalkyl group;
R4 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, acyl, acyloxy, alkoxy, alkoxycarbonyl, aminoacyl, aminoacyloxy, aryloxy, carboxyl, hydroxy, keto, thioalkoxy, thioaryloxy, xe2x95x90Nxe2x80x94ORd where Rd is hydrogen or alkyl, and a covalent bond attaching the ligand to a linker; or R4 together with the carbon atom to which it is attached represents a spiro-attached cycloalkyl group;
R5 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, acyl, acyloxy, alkoxy, alkoxycarbonyl, aminoacyl, aminoacyloxy, aryloxy, carboxyl, hydroxy, keto, thioalkoxy, thioaryloxy, xe2x95x90Nxe2x80x94ORd where Rd is hydrogen or alkyl, and a covalent bond attaching the ligand to a linker; or R2 together with the carbon atom to which it is attached represents a spiro-attached cycloalkyl group; and
a, b, c and d represent optional double bonds, provided that when a or c is a double bond, b is not a double bond; and when b or d is a double bond, c is not a double bond; and
W1 is xe2x80x94CH2CH2xe2x80x94;
provided that one of R2, R3, R4 or R5 is a covalent bond linking the ligand to a linker;
(b) a compound of formula IB: 
xe2x80x83wherein
A2 is selected from the group consisting of: 
where Ra, Rb and Rc are independently selected from the group consisting of hydrogen, lower alkyl and a pharmaceutically-acceptable cation;
R6 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkoxy, substituted alkoxy, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, aryl, substituted amino, heterocyclic, heteroaryl and a covalent bond attaching the ligand to a linker;
R7 is selected from the group consisting of hydrogen, alkyl, substituted alkyl, alkenyl, substituted alkenyl, alkoxy, substituted alkoxy, cycloalkyl, substituted cycloalkyl, cycloalkenyl, substituted cycloalkenyl, aryl, substituted amino, heterocyclic, heteroaryl, alkoxycarbonyl, cyano, carboxyl and a covalent bond attaching the ligand to a linker;
R8 and R9 are independently selected from the group consisting of hydrogen, alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, aralkyl and aralkoxy;
W2 is xe2x80x94CH2CH2xe2x80x94, xe2x80x94CHxe2x95x90CHxe2x80x94 or xe2x80x94Cxe2x95x90xe2x80x94;
provided that one of R6 or R7 is a covalent bond linking the ligand to a linker;
(c) a compound of formula IC: 
xe2x80x83wherein
A1 is as defined above;
R10 is selected from the group consisting of cycloalkyl and aryl;
one of R11 and R12 is xe2x80x94C(O)NR14R15 where R14 and R15 are independently selected from the group consisting of hydrogen, alkyl, aryl and a covalent bond attaching the ligand to a linker; and the other of R11 and R12 is selected from the group consisting of hydrogen, alkyl, cycloalkyl and a covalent bond attaching the ligand to a linker;
R13 is selected from the group consisting of alkyl, cycloalkyl and trifluoromethyl;
W3 is xe2x80x94CH2xe2x80x94, xe2x80x94CH2CH2xe2x80x94, xe2x80x94CH2CH2CH2xe2x80x94 or xe2x80x94CH2CH(CH3)xe2x80x94;
provided that one of R11, R12, R14 or R15 is a covalent bond linking the ligand to a linker; and
(d) a compound of formula ID: 
xe2x80x83wherein
A1 is as defined above;
one of R16 and R17 is aryl; and the other of R16 and R17 is selected from the group consisting of alkyl, cycloalkyl and aralkyl;
R18 and R19 are independently selected from the group consisting of hydrogen, alkyl, cycloalkyl, alkoxy, halo, aryloxy, aralkoxy and a covalent bond attaching the ligand to a linker; and
W4 is xe2x80x94CH2xe2x80x94, xe2x80x94CH2CH2xe2x80x94, xe2x80x94CH2CH2CH2xe2x80x94 or xe2x80x94CHxe2x95x90CHxe2x80x94;
provided that one of R18 or R19 is a covalent bond linking the ligand to a linker;
and pharmaceutically-acceptable salts thereof.
In still another of its composition aspects, this invention provides a multibinding compound of formula II:
Lxe2x80x2xe2x80x94Xxe2x80x2xe2x80x94Lxe2x80x2xe2x80x83xe2x80x83II
wherein each Lxe2x80x2 is independently a ligand comprising a moiety capable of binding to 3-hydroxy-3-methylglutaryl coenzyme A reductase; and Xxe2x80x2 is a linker;
and further wherein the distance between the ligands is at least 10 xc3x85; and pharmaceutically-acceptable salts thereof.
Preferably, each ligand, Lxe2x80x2, in the multibinding compound of formula II is independently selected from the group consisting of:
(a) a compound of formula IIA: 
xe2x80x83wherein
A1 is selected from the group consisting of: 
where Ra is selected from the group consisting of hydrogen, lower alkyl and a pharmaceutically-acceptable cation;
R21 is selected from the group consisting of hydrogen, lower alkyl, hydroxy and a covalent bond attaching the ligand to a linker;
R22, R23 and R24 are independently selected from the group consisting of hydrogen and a covalent bond attaching the ligand to a linker; and
e and f represent optional double bonds;
provided that one of R21, R22, R23 or R24 is a covalent bond linking the ligand to a linker;
(1)) a compound of formula IIB: 
xe2x80x83wherein
A1 is as define above;
R25 is selected from the group consisting of hydrogen, alkyl, alkoxyalkyl and a covalent bond attaching the ligand to a linker; and
R26 is selected from the group consisting of hydrogen, alkyl, cycloalkyl and a covalent bond attaching the ligand to a linker;
provided that one of R25 or R26 is a covalent bond linking the ligand to a linker;
(c) a compound of formula IIC: 
xe2x80x83wherein
A1 is as defined above;
R27 is selected from the group consisting of hydrogen and a covalent bond attaching the ligand to a linker; and
R28 is selected from the group consisting of amino, substituted amino and a covalent bond attaching the ligand to a linker;
provided that one of R27 or R28 is a covalent bond linking the ligand to a linker; and
(d) a compound of formula IID: 
xe2x80x83wherein
A1 is as defined above; and
R29 is a covalent bond attaching the ligand to a linker;
and pharmaceutically-acceptable salts thereof.
In a preferred embodiment, this invention is also directed to a multibinding compound of formula III: 
wherein
each A1 is independently selected from the group consisting of: 
where Ra is selected from the group consisting of hydrogen, lower alkyl and a pharmaceutically-acceptable cation; and Xxe2x80x3 is a linker; and further wherein the distance between ligands is at least 10 xc3x85; and pharmaceutically-acceptable salts thereof.
In another preferred embodiment, this invention is directed to a multibinding compound of formula IV: 
wherein
each A1 is independently selected from the group consisting of: 
where Ra is selected from the group consisting of hydrogen, lower alkyl and a pharmaceutically-acceptable cation; and Xxe2x80x3 is a linker; and further wherein the distance between ligands is at least 10 xc3x85; and pharmaceutically-acceptable salts thereof.
Preferably, in the above embodiments, each linker (i.e., X, Xxe2x80x2 or Xxe2x80x3) independently has the formula:
xe2x80x94Xaxe2x80x94Zxe2x80x94(Yaxe2x80x94Z)mxe2x80x94Ybxe2x80x94Zxe2x80x94Xaxe2x80x94
wherein
m is an integer of from 0 to 20;
Xa at each separate occurrence is selected from the group consisting of xe2x80x94Oxe2x80x94, xe2x80x94Sxe2x80x94, xe2x80x94NRxe2x80x94, xe2x80x94C(O)xe2x80x94, xe2x80x94C(O)Oxe2x80x94, xe2x80x94C(O)NRxe2x80x94, xe2x80x94C(S), xe2x80x94C(S)Oxe2x80x94, xe2x80x94C(S)NRxe2x80x94 or a covalent bond where R is as defined below;
Z is at each separate occurrence is selected from the group consisting of alkylene, substituted alkylene, cycloalkylene, substituted cylcoalkylene, alkenylene, substituted alkenylene, alkynylene, substituted alkynylene, cycloalkenylene, substituted cycloalkenylene, arylene, heteroarylene, heterocyclene, or a covalent bond;
Ya and Yb at each separate occurrence are selected from the group consisting of xe2x80x94C(O)NRxe2x80x2xe2x80x94, xe2x80x94NRxe2x80x2C(O)xe2x80x94, xe2x80x94NRxe2x80x2C(O)NRxe2x80x2xe2x80x94, xe2x80x94C(xe2x95x90NRxe2x80x2)xe2x80x94NRxe2x80x2xe2x80x94, xe2x80x94NRxe2x80x2xe2x80x94C(xe2x95x90NRxe2x80x2)xe2x80x94, xe2x80x94NRxe2x80x2xe2x80x94C(O)xe2x80x94Oxe2x80x94, xe2x80x94Nxe2x95x90C(Xa)xe2x80x94NRxe2x80x2xe2x80x94, xe2x80x94P(O)(ORxe2x80x2)xe2x80x94Oxe2x80x94, xe2x80x94S(O)nCRxe2x80x2Rxe2x80x3xe2x80x94, xe2x80x94S(O)nxe2x80x94NRxe2x80x2xe2x80x94, xe2x80x94Sxe2x80x94Sxe2x80x94 and a covalent bond; where n is 0, 1 or 2; and R, Rxe2x80x2 and Rxe2x80x3 at each separate occurrence are selected from the group consisting of hydrogen, alkyl, substituted alkyl, cycloalkyl, substituted cycloalkyl, alkenyl, substituted alkenyl, cycloalkenyl, substituted cycloalkenyl, alkynyl, substituted alkynyl, aryl, heteroaryl and heterocyclic.
In yet another of its composition aspects, this invention provides a pharmaceutical composition comprising a pharmaceutically acceptable carrier and an effective amount of a multibinding compound comprising from 2 to 10 ligands covalently attached to one or more linkers, wherein each of said ligands independently comprises a moiety capable of binding to 3-hydroxy-3-methylglutaryl coenzyme A reductase and further wherein the distance between ligands is at least 10 xc3x85; and pharmaceutically acceptable salts thereof.
This invention is also directed to pharmaceutical compositions comprising a pharmaceutically acceptable carrier and an effective amount of a multibinding compound of formula I, II, III or IV.
The multibinding compounds of this invention are effective inhibitors of the enzyme 3-hydroxyl-3-methylglutaryl-Coenzyme A reductase (HMG-COA reductase), an enzyme involved in the biosynthesis of cholesterol. Accordingly, in one of its method aspects, this invention provides a method for reducing cholesterol biosynthesis in a mammal comprising administering to said mammal an effective amount of a pharmaceutical composition comprising a pharmaceutically acceptable carrier and a multibinding compound comprising from 2 to 10 ligands covalently attached to one or more linkers, wherein each of said ligands independently comprises a moiety capable of binding to 3-hydroxy-3-methylglutaryl coenzyme A reductase and further wherein the distance between ligands is at least 10 xc3x85; and pharmaceutically acceptable salts thereof.
This invention is also directed to general synthetic methods for generating large libraries of diverse multimeric compounds which multimeric compounds are candidates for possessing multibinding properties for 3-hydroxy-3-methylglutaryl coenzyme A reductase. The diverse multimeric compound libraries provided by this invention are synthesized by combining a library of linkers with a library of ligands each having complementary functional groups permitting covalent linkage. The library of linkers is preferably selected to have diverse properties such as valency, linker length, linker geometry and rigidity, hydrophilicity or hydrophobicity, amphiphilicity, acidity, basicity, polarizability and polarization. The library of ligands is preferably selected to have diverse attachment points on the same ligand, different functional groups at the same site of otherwise the same ligand, and the like.
Additionally, this invention is directed to libraries of diverse multimeric compounds which multimeric compounds are candidates for possessing multibinding properties for 3-hydroxy-3-methylglutaryl coenzyme A reductase. These libraries are prepared via the methods described above and permit the rapid and efficient evaluation of what molecular constraints impart multibinding properties to a ligand or a class of ligands for 3-hydroxy-3-methylglutaryl coenzyme A reductase.
Accordingly, in one of its method aspects, this invention is directed to a method for identifying multimeric ligand compounds possessing multibinding properties for 3-hydroxy-3-methylglutaryl coenzyme A reductase, which method comprises:
(a) identifying a ligand or a mixture of ligands wherein each ligand contains at least one reactive functionality;
(b) identifying a library of linkers wherein each linker in said library comprises at least two functional groups having complementary reactivity to atxe2x80x2least one of the reactive functional groups of the ligand;
(c) preparing a multimeric ligand compound library by combining at least two stoichiometric equivalents of the ligand or mixture of ligands identified in (a) with the library of linkers identified in (b) under conditions wherein the complementary functional groups react to form a covalent linkage between said linker and at least two of said ligands; and
(d) assaying the multimeric ligand compounds produced in the library prepared in (c) above to identify multimeric ligand compounds possessing multibinding properties for 3-hydroxy-3-methylglutaryl coenzyme A reductase.
In another of its method aspects, this invention is directed to a method for identifying multimeric ligand compounds possessing multibinding properties for 3-hydroxy-3-methylglutaryl coenzyme A reductase, which method comprises:
(a) identifying a library of ligands wherein each ligand contains at least one reactive functionality;
(b) identifying a linker or mixture of linkers wherein each linker comprises at least two functional groups having complementary reactivity to at least one of the reactive functional groups of the ligand;
(c) preparing a multimeric ligand compound library by combining at least two stoichiometric equivalents of the library of ligands identified in (a) with the linker or mixture of linkers identified in (b) under conditions wherein the complementary functional groups react to form a covalent linkage between said linker and at least two of said ligands; and
(d) assaying the multimeric ligand compounds produced in the library prepared in (c) above to identify multimeric ligand compounds possessing multibinding properties for 3-hydroxy-3-methylglutaryl coenzyme A reductase.
Preferably, in these methods, the preparation of the multimeric ligand compound library is achieved by either the sequential or concurrent combination of the two or more stoichiometric equivalents of the ligands identified in (a) with the linkers identified in (b).
Additionally, the multimeric ligand compounds comprising the multimeric ligand compound library are preferably dimeric. In one embodiment, the dimeric ligand compounds comprising the dimeric ligand compound library are heterodimeric. The heterodimeric ligand compound library is preferably prepared by sequential addition of a first and second ligand.
In a preferred embodiment of the above methods, prior to procedure (d), each member of the multimeric ligand compound library is isolated from the library. More preferably, each member of the library is isolated by preparative liquid chromatography mass spectrometry (LCMS).
In the above methods, the linker or linkers employed are preferably selected from the group comprising flexible linkers, rigid linkers, hydrophobic linkers, hydrophilic linkers, linkers of different geometry, acidic linkers, basic linkers, linkers of different polarization and/or polarizability and amphiphilic linkers. More preferably, the linkers comprise linkers of different chain length and/or having different complementary reactive groups. Still more preferably, the linkers are selected to have different linker lengths ranging from about 10 to 100 xc3x85.
The ligand or mixture of ligands employed in the above methods is preferably selected to have reactive functionality at different sites on said ligands. More preferably, the reactive functionality is selected from the group consisting of carboxylic acids, carboxylic acid halides, carboxyl esters, amines, halides, pseudohalides, isocyanates, vinyl unsaturation, ketones, aldehydes, thiols, alcohols, anhydrides, boronates, and precursors thereof wherein the reactive functionality on the ligand is selected to be complementary to at least one of the reactive groups on the linker so that a covalent linkage can be formed between the linker and the ligand.
In one preferred embodiment of the above methods, the multimeric ligand compound library comprises homomeric ligand compounds. In another preferred embodiment, the multimeric ligand compound library comprises heteromeric ligand compounds.
In one of its composition aspects, this invention is directed to a library of multimeric ligand compounds which may possess multivalent properties for 3-hydroxy-3-methylglutaryl coenzyme A reductase, which library is prepared by the method comprising:
(a) identifying a ligand or a mixture of ligands wherein each ligand contains at least one reactive functionality;
(b) identifying a library of linkers wherein each linker in said library comprises at least two functional groups having complementary reactivity to at least one of the reactive functional groups of the ligand; and
(c) preparing a multimeric ligand compound library by combining at least two stoichiometric equivalents of the ligand or mixture of ligands identified in (a) with the library of linkers identified in (b) under conditions wherein the complementary functional groups react to form a covalent linkage between said linker and at least two of said ligands.
In another of its composition aspects, this invention is directed to a library of multimeric ligand compounds which may possess multivalent properties for 3-hydroxy-3-methylglutaryl coenzyme A reductase, which library is prepared by the method comprising:
(a) identifying a library of ligands wherein each ligand contains at least one reactive functionality;
(b) identifying a linker or mixture of linkers wherein each linker comprises at least two functional groups having complementary reactivity to at least one of the reactive functional groups of the ligand; and
(c) preparing a multimeric ligand compound library by combining at least two stoichiometric equivalents of the library of ligands identified in (a) with the linker or mixture of linkers identified in (b) under conditions wherein the complementary functional groups react to form a covalent linkage between said linker and at least two of said ligands.
In a preferred embodiment, the linker or linkers employed are preferably selected from the group comprising flexible linkers, rigid linkers, hydrophobic linkers, hydrophilic linkers, linkers of different geometry, acidic linkers, basic linkers, linkers of different polarization and/or polarizability and amphiphilic linkers. More preferably, the linkers comprise linkers of different chain length and/or having different complementary reactive groups. Still more preferably, the linkers are selected to have different linker lengths ranging from about 10 to 100 xc3x85.
In the above libraries, the ligand or mixture of ligands is preferably selected to have reactive functionality at different sites on said ligands. Preferably, the reactive functionality is selected from the group consisting of carboxylic acids, carboxylic acid halides, carboxyl esters, amines, halides, pseudohalides, isocyanates, vinyl unsaturation, ketones, aldehydes, thiols, alcohols, anhydrides, boronates, and precursors thereof wherein the reactive functionality on the ligand is selected to be complementary to at least one of the reactive groups on the linker so that a covalent linkage can be formed between the linker and the ligand.
In one embodiment, the multimeric ligand compound library comprises homomeric ligand compounds (i.e., each of the ligands is the same, although it may be attached at different points). In another embodiment, the multimeric ligand compound library comprises heteromeric ligand compounds (i.e., at least one of the ligands is different from the other ligands).
In another of its method aspects, this invention is directed to an iterative method for identifying multimeric ligand compounds possessing multibinding properties for 3-hydroxy-3-methylglutaryl coenzyme A reductase, which method comprises:
(a) preparing a first collection or iteration of multimeric compounds which is prepared by contacting at least two stoichiometric equivalents of the ligand or mixture of ligands which target a receptor with a linker or mixture of linkers wherein said ligand or mixture of ligands comprises at least one reactive functionality and said linker or mixture of linkers comprises at least two functional groups having complementary reactivity to at least one of the reactive functional groups of the ligand wherein said contacting is conducted under conditions wherein the complementary functional groups react to form a covalent linkage between said linker and at least two of said ligands;
(b) assaying said first collection or iteration of multimeric compounds to assess which if any of said multimeric compounds possess multibinding properties for 3-hydroxy-3-methylglutaryl coenzyme A reductase;
(c) repeating the process of (a) and (b) above until at least one multimeric compound is found to possess multibinding properties for 3-hydroxy-3-methylglutaryl coenzyme A reductase;
(d) evaluating what molecular constraints imparted or are consistent with imparting multibinding properties to the multimeric compound or compounds found in the first iteration recited in (a)-(c) above;
(e) creating a second collection or iteration of multimeric compounds which elaborates upon the particular molecular constraints imparting multibinding properties to the multimeric compound or compounds found in said first iteration;
(f) evaluating what molecular constraints imparted or are consistent with imparting enhanced multibinding properties to the multimeric compound or compounds found in the second collection or iteration recited in (e) above;
(g) optionally repeating steps (e) and (f) to further elaborate upon said molecular constraints.
Preferably, steps (e) and (f) are repeated from 2-50 times. More preferably, steps (e) and (f) are repeated from 5-50 times.
Preferably, the ligands employed in the above methods and library compositions are selected from ligands of formula IA-ID, more preferably, from ligands of formula IIA-IID.